1. Field of the Invention
This invention concerns a heating electrode device for medical use and, particularly, it relates to a high-frequency heating electrode device for medical use that can be applied to the hyperthermia of tumor, etc.
2. Description of the Related Art
High-frequency hyperthermia has been known in which therapy is carried out by applying heat to a lesional portion of a patient, utilizing the fact that cancer cells, etc. are less resistant to heat than normal cells.
In the conventional high-frequency heating method, hyperthermia is carried out by putting a region including an aimed portion to be heated of a living body between two opposed plate-like electrodes and applying a high-frequency current between the electrodes from a high-frequency generator.
In this case, because of the difference in electrical constants (electroconductivity and dielectric constant) between a subcutaneous fat layer and an endotract organ tissue, the subcutaneous fat layer tends to be heated more intensely, or a patient may complain of undesirable feeling of heat, or the epidermal tissue may suffer from burns due to the intense heating at a portion near the electrode body. Accordingly, there has been proposed a method of attaching a flexible and gastight bag member between a living body and electrode body and filling or circulating a coolant into or through the inside of the bag member. However, although there is no trouble so long as the device operates normally, if any unexpected accident should occur such as change of the introduction pressure, interruption or leakage of a coolant, the electrode body may possibly be brought into a close contact with the living body thereby causing an anxiety in view of the safety. In addition, it is generally necessary to provide the electrode device of this type with an additional device for securing the electrode device to the intended portion to be heated at the inside or the outside of the living body.